A random variable is normally distributed with a mean of 25 and a standard deviation of 5.If an observation is randomly selected from the distribution,what value will be exceeded 10% of the time?
A)31.40
B)28.60
C)66.23
D)14.56

Question

Quizplus · Accepted Answer

To find the value exceeded 10% of the time, we need to find the 90th percentile of the normal distribution. Using the Z-table, the Z-score for 0.90 is approximately 1.28. Using the formula X = μ + Zσ, where μ = 25 and σ = 5, we get X = 25 + 1.28(5) = 31.40.

A Random Variable Is Normally Distributed with a Mean of 25